Preventive effects of baker's yeast-derived β-glucan on hypercholesterolemia in rats

It is known that water-soluble fibers including β-glucans derived from oat and barley decrease cholesterol level in the plasma and liver, but the effects of baker's yeast derived β-glucan (BBG) are not fully understood yet. In this study, the effects of BBG on cholesterol absorption and excretion were compared with those of cellulose (CE) as a negative control fiber. Rats were fed with AIN-93M-based diet containing BBG or CE at 5% as a dietary fiber, and 2% cholesterol (CHL) or 0.5% cholesterol/0.2% sodium cholate (CA) for 4 weeks. In the CE-fed group, CHL and CA supplementation resulted in an elevation of total cholesterol level in the plasma, whereas BBG tended to inhibit this elevation. On the other hand, high density lipoprotein (HDL) cholesterol level in the plasma was significantly decreased by CHL and CA supplementation in the CE-fed group but not in the BBG-fed group. Moreover, BBG tended to inhibit hepatic hypertrophy and to reduce the increased fecal cholesterol level. These results indicate that BBG decreases plasma cholesterol level by stimulating the excretion of cholesterols. In conclusion, BBG is a highly functional dietary fiber more capable of preventing hypercholesterolemia and its related cardiovascular disease and arteriosclerosis than CE.